Liquid crystal display devices include a thin film transistor substrate (hereinafter referred to as a TFT substrate), a color filter substrate facing the TFT substrate (hereinafter referred to as a CF substrate), and a liquid crystal layer sandwiched between the TFT substrate and the CF substrate. In the CF substrate, colored portions for transmitting light of different colors (for example, red, green, and blue) and light shielding sections (hereinafter referred to as a black matrix) arranged in a boundary between the respective colored portions are formed. A known problem with conventional liquid crystal display devices is that color mixing occurs due to light leakage from adjacent pixel regions. The color mixing is caused, for example, by positional deviation or the like when the TFT substrate and the CF substrate are glued together. The color mixing is noticeably observed particularly when the viewing direction is oblique, which may degrade the display quality. For example, when a red image is displayed and the red pixels are viewed from an oblique direction, the red pixels display a color mixed with green or blue.
Technology for reducing color mixing is disclosed in the prior art. In a prior-art liquid crystal display device, regions where amount of misalignment when the TFT substrate and the CF substrate are glued together has been taken into consideration, and regions where light shielding when the display screen is viewed from an oblique direction has been taken into consideration are added to regions for forming the black matrix (See Japanese unexamined published patent application No. H11-72801).
However, in the prior-art technology, owing to enlarged width of the black matrix, a problem of the aperture ratio of the pixels decreasing has arisen.